The present invention relates to an ink jet recording apparatus comprising an ink jet recording head, which is mounted on a carriage that moves in the widthwise direction of a recording sheet and which ejects ink droplets through nozzle orifices. In particular, the present invention pertains to an ink jet recording apparatus that can restrict the splashing of ink that occurs due to the strength of the recovery force exerted by a wiping member, provided to wipe the nozzle formation face of the recording head.
Since ink jet recording apparatuses produce comparatively little noise during printing and can form small dots at a high density, they are currently being used for various types of printing, including color printing.
Such an ink jet recording apparatus comprises an ink jet recording head, mounted on a movable carriage, for receiving ink from an ink cartridge, and a paper feeder for moving a recording sheet relative to the recording head. To perform the printing function, while the recording head moves with the carriage in the widthwise direction of the recording sheet, ink droplets are ejected and are deposited on the recording sheet.
The recording head that is mounted on the carriage can eject black, yellow, cyan and magenta colored inks, so that not only can black be used for printing test, but also, full color printing is possible by changing the ejection ratio of the colored inks.
To print, droplets of ink are ejected under pressure, produced by a pressure generation chamber, through nozzles in the recording head mounted in the ink jet recording apparatus and are deposited on the recording sheet. Therefore, printing failures may occur as a result of a rise in ink viscosity, caused by the evaporation of solvent through the nozzle orifices, the solidification of ink, the attachment of dust particles to the nozzles, or the entry of air bubbles into the nozzle orifices.
Therefore, additional components provided for an ink jet recording apparatus comprise: a capping member, for sealing the nozzle orifices of a recording head while printing is not being performed, and a wiping member, for cleaning a nozzle plate.
The capping member serves as a lid to prevent ink from drying in the nozzle orifices of the recording head while printing is not being performed. In addition, when ink in the nozzle orifices of a recording head solidifies, clogging the nozzles, to eliminate the clogging, the capping member is used to seal the nozzle formation face while a suction pump applies a negative pressure to attract and discharge ink from the nozzle. The capping member also performs a similar function to eliminate an ink ejection failure resulting from the entry of air bubbles into the ink flow path.
The forcible ink suction and discharge process for removing clogging from a recording head and for preventing air bubbles from entering the ink flow path is called a cleaning process. This process is performed when printing is resumed after an apparatus has been halted for an extended period of time, or when a user notices a deterioration in image quality and turns on a cleaning switch.
The capping member permits the recording head to discharge ink under negative pressure, and a wiping member, which is an elastic plate, made of rubber, for example, cleans (wipes) the nozzle formation face of the recording head by wiping and scraping off ink adhering to the nozzle formation face.
In a wiping process that is performed after ink has been drawn into a recording head and discharged, a wiping member, composed, as previously mentioned, of an elastic material such as rubber, is advanced along the route traveled by the carriage on which the recording head is mounted, and wipes the nozzle formation face of the recording head as the carriage is moved.
As a result, ink adhering to the nozzle formation face of the recording head is removed and the nozzle formation face is cleaned.
In this case, the wiping member, while sliding in contact with the nozzle formation face, is appropriately bent, and the recovery force that is exerted during the wiping process is utilized to scrape ink from the nozzle formation face.
Therefore, while the carriage is being moved, at the moment at which the recording head passes beyond the location of the wiping member, the flexible recovery force of the wiping member causes the wiping member to rapidly recover to its original shape, and to splash, inside the ink jet apparatus, the ink that was scraped off the nozzle formation face.
In response to the immediate recovery effected by the wiping member, ink is splashed mainly on the capping member side, and contaminates a drive mechanism that is used to vertically move the capping member. When ink deposited on the drive mechanism solidifies, a technical problem arises, in that the ink interferes with the smooth operation of the drive mechanism, and the reliability of the apparatus is degraded.
To resolve the above shortcoming, it is one objective of the present invention to provide an ink jet recording apparatus that prevents ink retained on a wiping member from being splashed, and that can maintain the device reliability for an extended period of time.
In order to achieve the above object, according to the present invention, there is provided an ink jet recording apparatus comprising:
a carriage moving in a widthwise direction of a recording medium;
a recording head mounted on the carriage, and including a nozzle formation face having nozzle orifices from which ink drops are ejected for recording;
an elastic wiping member for wiping out ink on the nozzle formation face as the carriage is moved; and
a buffer member mounted on the carriage so as to be adjacent to the recording head, and having a contact face for receiving restoration force of the elastic wiping member produced by the wiping operation in order to prevent received ink from splashing therearound.
Preferably, the contact face of the ink remover is configured such that the distance between the nozzle formation face and the contact face of the buffer member increases so as to gradually restore the wiping member to the original shape thereof as the carriage moves.
Preferably, the contact face is a continuous slant face of a stepwise face.
Alternatively, a plurality of individual plate members, each having different length and arranged with a predetermined interval, constitute the contact face.
Preferably, the buffer member serves as an ink remover for removing the received ink on the wiping member.
Preferably, the contact face of the ink remover is configured such that the distance between the nozzle formation face and the contact face of the ink remover increases so as to gradually restore the wiping member to the original shape thereof as the carriage moves.
Preferably, the contact face is a continuous slant face or a stepwise face.
Alternatively, a plurality of individual plate members, each having different length and arranged with a predetermined interval, constitute the contact face.
Alternatively, the contact face of the ink remover is configured such that the distance between the nozzle formation face and the contact face of the ink remover decreases so as to further deform the wiping member as the carriage moves.
Preferably, the contact face is a continuous slant face or a stepwise face.
Alternatively, a plurality of individual plate members, each having different length and arranged with a predetermined interval, constitute the contact face.
Alternatively, a plurality of individual plate members, each having an identical length and arranged with a predetermined interval, constitute the contact face.
Alternatively, the contact face includes a groove. The contact face is configured such that the wiping member is momentarily restored to the original shape thereof, and ink splashed from the wiping member due to the restoration thereof is received by the groove.
According to the above configurations, the wiping member, immediately after cleaning the nozzle formation face of the recording head, slides in contact with the buffer member or the ink remover, and ink scraped off the nozzle formation face is removed.
Therefore, the problem encountered when ink scraped off the nozzle formation face is splashed within the apparatus, due to the restoration force of effected by a wiping member, can be eliminated.
Preferably, at least the contact face of the ink remover is made of a material capable of absorbing ink.
In this case, the ink absorption part absorbs or temporarily holds ink so that the removed ink can be naturally dried thereat.
As a result, the problem encountered when the driving mechanism for vertically moving a capping member is contaminated with ink can be eliminated, and operational reliability can be guaranteed for an extended period of time.
Preferably, the buffer member is mounted in an attachment area defined between a pair of guide protrusions formed on the carriage with a screw member screwed into the carriage while piercing the buffer member.
Preferably, the position of the buffer member in the carriage moving direction is determined by the position of the pair of guide protrusions. The buffer member includes a first positioning member to be engaged with one of the guide protrusions to determine the position of the buffer member in a direction perpendicular to the carriage moving direction.
Preferably, the buffer member includes a second positioning member to be engaged with one of the guide protrusions to determine the position of the buffer member in a direction orthogonal to a mount face of the attachment area, and a through hole, through which the screw member is inserted, formed to be adjacent to the other one of the guide protrusions to determine the position of the contact face.
According to the above configurations, the positioning and the attachment of the buffer member are quite easy, and this contributes. to an increase in productivity. Further, since the protrusion on the buffer member engages the guide protrusions at this time, the buffer member can also be positioned in the direction perpendicular to the carriage moving direction.
Furthermore, the contact face of the buffer member relative to the carriage can be uniquely defined, so that an excellent contact condition of the wiping member can be maintained, without product variances occurring.
Preferably, the ink jet recording apparatus further comprises a capping member for capping the nozzle formation face. The buffer member is located in a side close to the capping member with respect to the recording head.
The nozzle formation face of the recording head is sealed by the capping member, and a cleaning process is performed to attract and discharge ink using the negative pressure produced by a suction pump. Thereafter, as the carriage is moved to the printing area, the wiping member wipes off ink adhering to the nozzle formation face.
At this time, since the wiping member, which is bent while in contact with the recording head, gradually recovers to its original shape while sliding along the inclined face of the ink remover, a problem encountered when ink scraped off a nozzle formation face is splashed within an apparatus can be eliminated.